Zn:In(OH)ySz Solid Solution Nanoplates: Synthesis, Characterization, and Photocatalytic Mechanism

Zn:In(OH)(y)S-z solid solution nanoplates (Zn:In(OH)(y)S-z-SSNs) with uniform nanoparticle size were synthesized through a simple sodium dodecyl sulfate (SOS)-assisted hydrothermal process. To achieve better photoabsorption in the visible light K) region and suitable redox potentials of the Zn-In(OH)(y)S-z solid solution (Zn:In(OH)(y)S-z-SS), the substitution of S2- for OH- was carried out by adjusting the concentration of thiourea and SOS in the synthesis solution, while the doping of Zn2+ was realized by adjusting Zn2+ concentration. In addition, the morphology and crystallinity of Zn:In(OH)(y)S-z-SSs were also controlled by the concentration of SOS. Using Rhodamine B (RhB) as a target pollutant, the photocatalytic performance of these Zn:In(OH)(y)S-z-SSs with different components, diameter sizes, and morphologies was investigated. Remarkably, Zn:In(OH)(y)S-z-SSNs prepared with atomic ratio of Zn2+ and In3+ of 0.6, 45 mmol L-1 thiourea, and 26 mmol L- 1 SOS, have the highest visible-light-driven (VLD) photocatalytic activity, exceeding 95% for the degradation of RhB after 60 min. The investigation of photocatalytic mechanism further indicates that the holes, superoxide radical (center dot O-2(-)) and surficial hydroxyl radical (center dot OHs) are the major reactive species for the photocatalytic reactions. More importantly, for the first time, a simple and versatile strategy is developed to confirm the fact that direct contact between the Zn:In(OH)(y)S-z-SS and RhB is the prerequisite for the photocatalytic degradation of RhB. Therefore, we report not only the preparation of a novel and effective VL-driven photocatalyst, but also provide mechanistic insight into semiconductor photocatalysis.